Advertising-supported distribution of audio-video data may be implemented from a content server to remote client devices over computer networks, telecommunications networks, and combinations of such networks, using various methods, for example progressive downloading or streaming.
In streaming, a server streams audio-video data continuously to a media player component operating at least partly on the client device, which may play the audio-video data concurrently with receiving the streaming data from the server. The media player component may initiate play of the video data immediately after receiving an initial portion of the data from the content provider. Traditional streaming techniques use a single provider delivering a stream of data to a set of end users. High bandwidths and processing power may be required to deliver a single stream to a large audience, and the required bandwidth of the provider may increase as the number of end users increases.
Unlike progressive downloading, streaming media can be delivered on-demand or live. Progressive download requires downloading the entire file or downloading enough of the entire file to start playback at the beginning, whereas streaming enables immediate playback at any point within the file. End-users may skip through the media file to start playback or change playback to any point in the media file. Hence, the end-user does not need to wait for the file to progressively download. Typically, streaming media is delivered from a few dedicated servers having high bandwidth capabilities.
A streaming media server is a specialized device that accepts requests for video files, and with information about the format, bandwidth and structure of those files, delivers just the amount of data necessary to play the video, at the rate needed to play it. Streaming media servers may also account for the transmission bandwidth and capabilities of the media player on the destination client. Unlike the web server, the streaming media server communicates with the client device using control messages and data messages to adjust to changing network conditions as the video is played. These control messages can include commands for enabling control functions such as fast forward, fast reverse, pausing, or seeking to a particular part of the file at the client. Since a streaming media server transmits video data only as needed and at the rate that is needed, precise control over the number of streams served can be maintained. Unlike the case with progressive downloading, the viewer will not be able to view high data rate videos over a lower data rate transmission medium. However, streaming media servers (1) provide users random access to the video file, (2) allows monitoring of who is viewing what video programs and how long they are watched, (3) use transmission bandwidth more efficiently, since only the amount of data required to support the viewing experience is transmitted, and (4) the video file is not stored in the viewer's computer, but discarded by the media player, thus allowing more control over the content.
Streaming media servers may use HTTP and TCP to deliver video streams, but generally use RSTP (real time streaming protocol) and UDP (user datagram protocol). These protocols permit control messages and save bandwidth by reducing overhead. Unlike TCP, when data is dropped during transmission, UDP does not transmit resent requests. Instead, the server continues to send data. Streaming media servers can also deliver live webcasts and can multicast, which allows more than one client to tune into a single stream, thus saving bandwidth.
Typically, progressively downloaded media is transmitted to the user device at a rate that is faster than playback. The media program player buffers this data, and may indicate how much of the media program has been buffered by providing an indicator, usually as a part of a “progress bar.” A control is often provided that allows the user to go to any point in the program that has already been buffered by selecting the control and moving it to a different location along the progress bar. This allows the user to randomly access any buffered portion of the media program.
Streaming media players do not rely on buffering to provide random access to any point in the media program. Instead, this is accomplished through the use of control messages transmitted from the media player to the streaming media server.
The delivery of video content by streaming or progressive download may be accomplished under a variety of models. In one model, the user pays for the viewing of each video program, for example, using a pay-per-view service. In another model widely adopted by broadcast television shortly after its inception, sponsors pay for the presentation of the media program in exchange for the right to present advertisements during or adjacent to the presentation of the program. In some models, advertisements are inserted at predetermined times in a video program, which times may be referred to as “ad slots” or “ad breaks.” With streaming video, the media player may be configured so that the client device cannot play the video without also playing predetermined advertisements during the designated ad slots. While this feature is helpful for ensuring that ad impressions are delivered to the client device, a lack of ability for the user to influence or control the number of ad slots or advertising content played during the ad slots may reduce the interest of some viewers in viewing streaming video content with inserted advertising.
These and other limitations of prior method for controlling advertising inserted in streaming video or progressively downloaded video may be overcome by the novel methods and apparatus disclosed herein.